Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the readOnlyHint/openWorldHint annotations, the description discloses that the upstream service is public and open-world, that unknown IDs return 404, and — most valuably — the pricing model: $0.002 USDC per successful call via x402 on Base, Solana, or Arc, with failed calls not charged. Cost and billing semantics are exactly the kind of context annotations cannot express.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

It is one dense but well-ordered paragraph: payload contents first, accepted input second, error behavior third, pricing last. Every clause carries information, though the long parenthetical enumerating returned fields overlaps with the output schema and could be trimmed.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter lookup with an output schema, the definition covers scope, input forms, failure behavior, and payment, leaving little ambiguity. The slight redundancy with the output schema is harmless; nothing an agent needs to invoke it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and the single parameter is fully documented in the schema with the same ID-or-URL format. The description's restatement adds no syntax, validation, or edge-case detail beyond what the schema already provides, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific verb+resource (TikTok sound/music stats from the public embed player and sound page) and enumerates exactly what is returned: sound ID, title, artist, video count, cover image, and the first 10 videos with their fields. An agent can tell it is the sound-level lookup tool and not a video/profile tool without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives the concrete input condition (accepts a sound ID or a tiktok.com/music/... URL) and a useful failure mode (unknown sounds return 404). It does not name alternative tools or state exclusions, but none of the listed siblings perform TikTok sound lookups, so there is little to disambiguate against.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.